Go to the pharmacy or a lumber yard and ask for some oxalic acid. It’s a controlled substance, but if you put a little in your wash and/or rinse loads, it will take out the dinginess.
I used it in my laundry in Olympia, Washington, as the water there was rusty. Never had any rust stains in my clothes like other people did.
Should I look for Rit laundry treatment?
I don’t know if that’s the same thing, but you can try it. Like I say, oxalic acid is a controlled substance. It is used for bleaching wood, but some pharmacies carry it. Call a few and find out. If they ask you what it is, thank them for their time, and call someone else! Lumber yards or woodworking shops should have some or know where to get it.